U.S. patent number 6,738,123 [Application Number 08/814,082] was granted by the patent office on 2004-05-18 for drive circuit connection structure including a substrate, circuit board, and semiconductor device, and display apparatus including the connection structure.
This patent grant is currently assigned to Canon Kabushiki Kaisha. Invention is credited to Toshimichi Ouchi, Riichi Saito, Masanori Takahashi.
United States Patent |
6,738,123 |
Takahashi , et al. |
May 18, 2004 |
**Please see images for:
( Certificate of Correction ) ** |
Drive circuit connection structure including a substrate, circuit
board, and semiconductor device, and display apparatus including
the connection structure
Abstract
A circuit connection structure including a substrate, a circuit
board, a semiconductor, and a flexible wiring member. The substrate
has a part of a display panel and an electrode terminal formed
thereon. The circuit board is disposed with a space between it and
the substrate and has an electrode terminal. The semiconductor
device bridges the space between the substrate and the circuit
board and has a first electrode and a second electrode and includes
a driver IC. The flexible wiring member has a conductor, of which,
opposite ends are connected to the second electrode and the
electrode terminal of the circuit board, respectively. The driver
IC is connected to the substrate by connecting the first electrode
to the electrode terminal on the substrate. By connecting the
driver IC to the substrate in this manner, it becomes possible to
obviate a conventional thermal problem of positional deviation.
Inventors: |
Takahashi; Masanori (Chigasaki,
JP), Saito; Riichi (Fujisawa, JP), Ouchi;
Toshimichi (Yokohama, JP) |
Assignee: |
Canon Kabushiki Kaisha (Tokyo,
JP)
|
Family
ID: |
13119729 |
Appl.
No.: |
08/814,082 |
Filed: |
March 10, 1997 |
Foreign Application Priority Data
|
|
|
|
|
Mar 15, 1996 [JP] |
|
|
8/059665 |
|
Current U.S.
Class: |
349/152; 349/149;
349/150; 349/151; 257/E21.511; 257/E23.065 |
Current CPC
Class: |
H01L
24/81 (20130101); G02F 1/13452 (20130101); H01L
23/4985 (20130101); H01L 2924/01029 (20130101); H01L
2924/01082 (20130101); H01L 2924/014 (20130101); H01L
2924/01078 (20130101); H01L 2924/01079 (20130101); H01L
2924/07802 (20130101); H01L 2224/13144 (20130101); H01L
2224/81801 (20130101); H01L 2924/3011 (20130101); H01L
2924/01033 (20130101); H01L 2924/0102 (20130101); H01L
2924/0105 (20130101); H01L 2924/01057 (20130101); H01L
2924/07802 (20130101); H01L 2924/00 (20130101) |
Current International
Class: |
G02F
1/13 (20060101); H01L 21/60 (20060101); H01L
23/48 (20060101); H01L 23/498 (20060101); H01L
21/02 (20060101); G02F 001/134 () |
Field of
Search: |
;349/149-152 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Patent Abstracts Of Japan, vol. 096, No. 004, Apr. 30, 1996 &
JP 07 321152 A (Citizen Watch Co LTD), Dec. 8, 1995, * abstract *.
.
Patent Abstracts Of Japan, vol. 018, No. 612 (P-1829), Nov. 21,
1994 & JP 06 230405 A (NEC Corp), Aug. 19, 1994, * abstract * .
.
Patent Abstracts Of Japan, vol. 095, No. 002, Mar. 31, 1995 &
JP 06 313893 A (Kyocera Corp), Nov. 8, 1994, * abstract * . .
Patent Abstracts Of Japan, vol. 017, NO. 060 (P-1482), Feb. 5, 1993
& JP 04 269722 A (Rohm Co Ltd), Sep. 25, 1992, * abstract *
..
|
Primary Examiner: Ngo; Julie-Huyen L.
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper &
Scinto
Claims
What is claimed is:
1. A circuit connection structure, comprising: a substrate forming
a part of a display panel and having an electrode terminal formed
thereon; a circuit board disposed with a space between said circuit
board and said substrate and having thereon an electrode terminal;
a semiconductor device comprising a driver IC, said semiconductor
device having a first electrode and a second electrode; and a
flexible wiring member having a conductor, wherein opposite ends of
the conductor of said flexible wiring member are connected to the
second electrode and the electrode terminal of said circuit board,
respectively, and wherein said semiconductor device bridges the
space between the substrate and the circuit board such that the
driver IC is located over the space and the first electrode of the
semiconductor device is connected to the electrode terminal on the
substrate with an anisotropic conductive adhesive.
2. A connection structure according to claim 1, wherein in said
semiconductor device the first and second electrodes are structured
to act as output and input electrodes, respectively, thereof so as
to receive input data from the circuit board and supply output
signals to the substrate, thereby driving an electronic device.
3. A connection structure according to claim 1, wherein the second
electrode of the semiconductor device is connected to the conductor
on the flexible wiring member by a tape-automated bonding
method.
4. A connection structure according to claim 1, wherein the
connection between the second electrode of the semiconductor device
and the conductor ends of the conductors conductor on the flexible
wiring member is sealed with a resin.
5. A display apparatus, comprising: a display panel comprising at
least one substrate, said at least one substrate having thereon a
pixel electrode extending to form an electrode terminal on a
peripheral side of said at least one substrate; a semiconductor
device having an input electrode, and an output electrode for
supplying drive waveforms to the pixel electrode of the display
panel; and a circuit board disposed with a space between said
circuit board and said at least one substrate of the display panel
and having an electrode terminal for supplying an electric power
and control signals to the semiconductor device, wherein the
semiconductor device is connected to the circuit board via a
flexible wiring member disposed in a lateral position with respect
to said at least one substrate, said flexible wiring member having
thereon a conductor extending from a first conductor end to a
second conductor end so that the input electrode of the
semiconductor device is connected to the first conductor end, and
the second conductor end is connected to the electrode terminal of
the circuit board, and wherein said semiconductor device bridges
the space between said at least one substrate of the display panel
and the circuit board such that the driver IC is located over the
space and the output electrode of the semiconductor device is
connected to the electrode terminal on said at least one substrate
of the display panel with an anisotropic conductive adhesive.
6. A display apparatus according to claim 5, wherein the input
electrode of the semiconductor device is connected to the first
conductor end of the conductor on the flexible wiring member by a
tape-automated bonding method.
7. A display apparatus according to claim 5, wherein the connection
between the second electrode of the semiconductor device and the
first conductor end of the conductor on the flexible wiring member
is sealed with a resin.
Description
FIELD OF THE INVENTION AND RELATED ART
The present invention relates to a drive circuit connection
structure suitable for use in a display apparatus, and particularly
a connection structure including a drive semiconductor device
connected to a periphery of a transparent substrate of a display
panel constituting such a display apparatus and a circuit board
connected to the semiconductor device for supplying input signals
and a power to the semiconductor device.
Hitherto, there have been known display apparatus including flat
display devices having display electrodes arranged in the form of,
e.g., a matrix, such as EL display panels and liquid crystal
display panels of the simple matrix-type and the active
matrix-type. Such display apparatus have conventionally included a
circuit connection structure including a transparent substrate,
such as a glass substrate or a plastic substrate, provided with
display electrodes arranged in the form of, e.g., a matrix; a
flexible tape carrier package (TCP) loaded with a driver IC by the
TAB (tape-automated bonding) method; and a print circuit board
(PCB, hereinafter sometimes called "PCB board"), connected in this
order.
FIG. 12 and FIG. 13 (a view showing a 13-13 section in FIG. 12)
illustrate an example of such a drive circuit connection structure
for a flat display panel. Referring to these figures, the
connection structure includes TCPs 4ap and 8p loaded with driver
ICs (as drive semiconductor circuits) 5p and 9p and copper foil
patterns 32 (as output electrodes), glass substrates 1ap and 1bp
for a liquid crystal panel 1 having electrode terminals 12p
extended to peripheries thereof, and ACFs (anisotropic conductive
films or anisotropic conductive adhesive) 31 for heat-bonding the
copper foil patterns 32 on the TCPs with the electrode terminals
12p on the glass substrates. Further, PCB boards 3p for supplying a
power and control signals to the driver ICs 5p and 9p are connected
with copper foil patterns 17 (as input electrodes) of the TCPs 4ap
with solder 20p.
The input electrodes and the output electrodes of each driver IC 5p
are connected to the copper foil electrodes 17 and 32 on the input
side and output side TCPs 4a, respective via gold bumps 15p. The
connections of each driver IC 5p are sealed with a resinous sealing
agent 16p. In such a display panel connection structure for a
display apparatus as shown in FIGS. 12 and 13, as the display panel
(particularly a liquid crystal panel) is provided with a larger
number of display electrodes at a higher density, the connection
pitch for connection between the output electrodes of the TCPs and
the electrode terminals on the transparent substrates are decreased
down to a required pitch of 50 .mu.m or smaller. However, according
to a method for connecting TCP with a substrate as explained with
reference to FIGS. 12 and 13, a very sophisticated and accurate
bonding technique is required for ensuring such a minute connection
pitch because of a limitation in size accuracy of TCPs and a
deviation due to thermal expansion during connection by heat
bonding of TCPS. Therefore, a connection structure as shown in FIG.
14 including bonding of driver ICs 5 to a substrate 1bp by a
face-down mode has been proposed or ensuring such a minute
connection pitch.
More specifically, referring to FIG. 14, the connection structure
includes a connection by the face-down bonding mode of driver ICs 5
with electrode terminals extended to peripheries of a pair of glass
substrates 1ap and 1bp of a display panel and with input electrodes
(not shown) formed on the glass substrates 1ap and 1bp. The
connection structure further includes flat cables 7a, 7b and 7c for
supplying a drive power and control signals from an external
control circuit.
However, in case where such a connection structure as shown in FIG.
14 is adopted in a display panel of a larger size, particularly a
liquid crystal display panel of an enlarged size as desired, in
recent years, the substrates 1ap and 1bp retain only narrow
non-opposing peripheral areas while the input electrodes are
increased in length, so that the input electrodes are caused to
have a higher impedance, thus being liable to cause a delay in
transmission of drive waveforms to the display or pixel electrodes
leading to pixels.
In order to obviate the difficulty, it may be conceived of lowering
the impedance of the input electrodes by forming the electrodes in
a larger thickness, but the realization thereof is difficult in
view of the limitations from the production process and size.
Further, the increased impedance of the input electrodes is liable
to cause a mal-function of data transfer during transmission of
image data for a liquid crystal display panel of a higher
definition to driver ICs.
SUMMARY OF THE INVENTION
A generic of the present invention is to solve the above-mentioned
problems of the prior art.
A more specific object of the present invention is to provide a
circuit connection structure capable of providing a lower input
electrode impedance while ensuring a minute connection pitch.
Another object of the present invention is to provide a display
apparatus including such a circuit connection structure.
According to the present invention, there is provided a circuit
connection structure, comprising: a first substrate having
electrode terminals formed thereon, a semiconductor device having
first electrodes and second electrodes with the first electrodes
connected to the electrode terminals of the first substrate, a
flexible wiring member having thereon a pattern of conductors each
extending from a first end to a second end on the flexible wiring
member with the first ends of the conductors connected to the
second electrodes of the semiconductor device, and a circuit board
having thereon electrode terminals connected to the second ends of
the conductors on the flexible wiring member.
It is preferred that the first and second electrodes of the
semiconductor device are used as output electrodes and input
electrodes, respectively, of the semiconductor device, so as to
receive input data from the circuit board and supply output signals
to the first substrate, thereby driving an electronic device
including the first substrate.
The flexible wiring member may alternatively be constituted by a
plurality of conductor wires each extending from a first end to a
second end and not carried on a carrier film.
According to another aspect of the present invention, there is
provided a display apparatus, comprising: a display panel
comprising at least one substrate having thereon pixel electrodes
extending to form electrode terminals electrodes on a peripheral
side of the substrate, a semiconductor device having input
electrodes, and output electrodes for supplying drive waveforms to
the pixel electrodes of the display panel, and a circuit board
having electrode terminals for supplying an electric power and
control signals to the semiconductor device; wherein the electrode
terminals on said at least one substrate of the display panel are
connected to the output electrodes of the semiconductor device, and
the semiconductor device is connected to the circuit board via a
flexible wiring member having thereon a pattern of conductors each
extending from a first end to a second end so that the input
electrodes of the semiconductor device are connected to the first
ends of the conductors on the flexible wiring member, and the
second ends of the conductors of the flexible wiring member are
connected to the electrode terminals of the circuit board.
According to the circuit connection structure of the present
invention, the first electrodes on one side of the semiconductor
device may be connected to the electrode terminals on the first
substrate which may carry pixel electrodes thereon via, e.g., an
anisotropic conductive adhesive (ACF), etc., and without via a
flexible wiring member according to the TAB method, thereby
ensuring a minute connection pitch. On the other hand, the second
electrodes on the other side of the semiconductor device are
connected via conductors of the flexible wiring member to the
electrode terminals of the circuit board. Particularly when the
first and second electrodes of the semiconductor device are used as
the output and input electrodes, respectively, the semiconductor
device can be supplied with an electric power and control signals
at a low impedance from the circuit board through the flexible
wiring member and the second electrodes, and can supply output
signals through the first electrodes at a minute arrangement pitch
suitable for a high-definition output.
Particularly, if the circuit connection structure is included in a
driver IC connection structure for a display apparatus including
the first substrate as a substrate carrying pixel electrodes of a
display panel and the circuit board for supplying an electric power
and control signals to the driver IC, the semiconductor device can
be supplied with input data at a low impedance and without
mal-function and can supply drive signals to the display panel
through the first electrodes arranged at a minute connection pitch
suitable for a higher definition display.
These and other objects, features and advantages of the present
invention will become more apparent upon a consideration of the
following description of the preferred embodiments of the present
invention taken in conjunction with the accompanying drawings,
wherein like parts are denoted by like reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a display apparatus including a drive
circuit connection structure according to a first embodiment of the
invention.
FIG. 2 is a partial sectional view taken along a line 2--2 in FIG.
1.
FIGS. 3A-3C are partial plan views for illustrating steps of
bonding a driver IC onto a flexible wiring member in the display
apparatus of FIGS. 1 and 2.
FIG. 4 is a side sectional view of a resultant connection structure
including the driver IC and the flexible wiring member connected to
each other after the steps of FIGS. 3A-3C.
FIGS. 5-6 and 8-10 are partial sectional views of display apparatus
including drive circuit connection structures according to second
to sixth embodiments, respectively, of the invention.
FIG. 7 is a sectional view of a partial connection structure
incorporated in the embodiment of FIG. 8.
FIG. 11 is a block diagram of a liquid crystal display
apparatus.
FIG. 12 is a plan view of a liquid crystal display apparatus
including a drive circuit connection structure.
FIG. 13 is a partial sectional view taken along a line 13--13 in
FIG. 12.
FIG. 14 is a partial sectional view of a liquid crystal display
apparatus including another drive circuit connection structure.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a plan view of a liquid crystal display apparatus, as an
embodiment of display apparatus, including a drive circuit
connection structure according to a first embodiment of the present
invention, and FIG. 2 is a sectional view taken along a line 2--2
in FIG. 1. In FIGS. 1 and 2, reference numerals identical to those
used in FIGS. 12-13 denote identical or like parts as in FIGS.
12-13.
Referring to FIGS. 1 and 2, a liquid crystal display apparatus 1
includes a pair of transparent substrates 1a and 1b of, e.g.,
glass, a polarizer 2 (which sandwiches the liquid crystal panel 1
together with a polarizer (not shown) on an opposite side), circuit
boards 3 and 10 (of, e.g., a multi-layered glass epoxy PCB board)
for supplying a drive power and control signals to driver ICs 5 and
9, flexible wiring members 4a and 8, flat cables 6 for supplying
data signals to the circuit boards 3, and a flat cable 7 for
supplying a drive power and control signals from an external
control circuit (not shown). Referring to FIG. 2, a liquid crystal
11 (which is a ferroelectric liquid crystal in this embodiment but
can also be a nematic liquid crystal, etc.) is disposed between the
substrates 1a and 1b.
The substrates 1a and 1b are provided with electrodes for applying
a drive voltage to the liquid crystal 1, and at least one thereof
is provided with display electrodes or pixel electrodes leading to
or defining the pixels and supplying display data signals to the
respective pixels. The pixel electrodes extend to non-opposing
peripheries of the substrates 1a and/or the substrate 1b to form
electrode terminals thereat. In this embodiment, both substrates 1a
and 1b are provided with pixel electrodes so as to form a simple
matrix electrode structure suitable for driving the ferroelectric
liquid crystal including, e.g., data electrodes on the substrate 1a
and scanning electrodes on the substrate 1b, and the pixel
electrodes are extended to non-opposing peripheries of both
substrates 1a and 1b to form electrode terminals 12 thereat.
Each driver IC 5 is connected to electrode terminals 12 formed on
the glass substrate 1b and extended to a peripheral side of the
glass substrate 1b, and the input electrodes of the driver IC 5 are
provided in advance with gold bumps 15 to which first ends of
conductors on a flexible wiring member 4a are connected by the TAB
method, and second (the other) ends of conductors on the flexible
wiring member 4a are connected to electrode terminals of the
circuit board 3.
At the time of assembling the display apparatus, each driver IC 5
is connected to the glass substrate 1b by first positionally
aligning projection electrodes 13 (of, e.g., gold bumps formed on
the output electrodes) of the device IC 5 with the electrode
terminals 12 on the glass substrate 1b and connecting the
projection electrodes 13 and the electrode terminals 12 via an
anisotropic conductive adhesive 14 under application of heat and
pressure. The projection electrodes 13 (of e.g., gold bumps) may be
formed at a minute connection of preferably 50 .mu.m or smaller as
shown in FIGS. 3A-3C described hereinafter.
By connecting the driver IC 5 provided with the projection
electrodes 13 to the electrode terminals 12 of the glass substrate
1b without via a flexible wiring member 4a, it becomes possible to
obviate a thermal positional deviation due to heat during the
heat-pressure bonding, thus ensuring a prescribed connection
pitch.
On the other hand, the second ends of conductors 17 (patterned
copper foil of, e.g., 15-35 .mu.m in thickness) on the flexible
wiring member 4a which have been connected in advance at their
first ends to the input electrodes of the driver IC are connected
to connection electrodes (electrode terminals) 19 of the circuit
board 3 by heat-pressure bonding via an anisotropic conductive
adhesive 18.
The copper foil electrodes 17 of the flexible wiring member 4a and
the anisotropic conductive adhesive 18 respectively have prescribed
thicknesses so that the conductors between the driver IC 5 and the
circuit board 3 may have a lower impedance.
By supplying input signals to the driver IC 5 through low-impedance
conductors 17 in the above-described manner, it becomes possible to
obviate a delay in transmission of drive waveforms and a
mal-function during data transmission. Incidentally, the
anisotropic conductive adhesive 14 for connecting the electrode
terminals 12 on the glass substrate 1b and the output electrodes of
the driver IC 5, and the anisotropic conductive adhesive 18 for
connecting the copper foil electrodes 17 on the flexible wiring
member 4a and the connection electrodes 19 of the circuit board 3,
may respectively be composed by selecting electroconductive
particles and an adhesive suitable therefor and need not be
identical to each other.
More specifically, in the above-described embodiment, a
commercially available anisotropic conductive film (ACF) may be
used as the anisotropic conductive adhesive 18. Generally, however,
the anisotropic conductive adhesive 18 may comprise a liquid
insulating adhesive of heat-curable type or UV-curable type
containing electroconductive particles dispersed therein.
Alternatively it is also possible to use such a liquid insulating
adhesive together with gold bumps formed on the electrode
terminals. Examples of the electroconductive particles may include
Ni-plated or Ni--Au-plated resin particles of 2-5 .mu.m in diameter
for output electrode connection and Ni particles or Au-plated Ni
particles of 5-10 .mu.m in diameter for input electrode
connection.
In the embodiment shown in FIG. 1, the circuit connection structure
characteristic to the present invention as described above is
applied to peripheral sides of only one substrate 1b of the display
panel 1, and at a peripheral side of the other substrate 1a,
drivers IC 9 are connected via a TCP with respect to both input
side and output side thereof similarly as in the case of FIG. 12.
However, it is also possible to adopt the circuit connection
structure having a sectional structure as shown in FIG. 2 for
bonding the driver ICs 9 to the substrate 1a similarly as the
driver ICs 5 connected to the substrate 1b.
Then, a flexible wiring member 4a may be connected to a driver IC 5
by the TAB method, for example, in the following manner.
First of all, as shown in FIG. 3A, an aperture 24 is formed in a
film carrier 4 of, e.g., polyimide or polyethylene terephthalate of
ca. 25-125 .mu.m in thickness, and tin-plated copper foil
conductors 17 and 17a are formed thereon. Then, gold bumps 15 (FIG.
2) formed on input electrodes of the driver IC 5 are positionally
aligned with the copper foil patterns 17 and 17a and subjected to
inner lead bonding by means of a bonding tool. Instead of the
above-mentioned tin plating of, e.g., 0.2-0.6 .mu.m in thickness,
it is also possible to use 0.2-10 .mu.m-thick solder, 0.2-0.9
.mu.m-thick gold or 0.2-10 .mu.m-thick Ni for coating the copper
foil conductors 17 and 17a.
The copper foil patterns 17a are used as support patterns for
fixing the driver IC and connected to dummy gold bumps (not shown)
formed on the driver IC 5. However, it is also possible to dispose
additional input electrodes there that can be connected to and
receive signals from the flexible wiring member 4a.
Then, as shown in FIG. 3B, only the input side of the driver IC 5
is sealed with a resinous sealing agent 16. Then, an unnecessary
portion of the flexible wiring member 4a is removed by punching to
leave a connection structure having a planar structure as shown in
FIG. 3C and a sectional structure as shown in FIG. 4.
In this instance, the gold bumps (projecting electrodes) 13 on the
output electrodes of the driver IC may preferably be flattened by
the bonding tool at the time of the inner lead bonding or by
pressing with another flattening pressure member so as to provide a
uniform projection height, in order to provide a reliable bonding
between the electrode terminals 12 and the output electrodes 5 of
the driver IC 4 with an anisotropic conductive adhesive 14.
In a preferred example of circuit connection structure adopted for
constituting a liquid crystal apparatus, each driver IC may have
ca. 30-60 input electrodes (second electrodes) arranged at a pitch
of ca. 100-500 .mu.m in both cases of constituting a data signal
side IC and a scanning signal side IC. Further, each driver IC may
have ca. 200-500 output electrodes (first electrodes) arranged at a
pitch of ca. 20-60 .mu.m when used as a data signal side IC and at
a pitch of ca. 100-300 .mu.m when used as a scanning signal side
IC. The circuit connection structure according to the present
invention may be adopted for both data signal side ICs and scanning
signal side IC but may preferably be used at least for data signal
side ICs requiring output electrodes (first electrodes) arranged at
a higher density in the embodiment of FIG. 1.
Further to say, in a drive system using a liquid crystal showing
bistability, such as a ferroelectric liquid crystal, an
anti-ferroelectric liquid crystal or a BTN-mode liquid crystal
driven in a binary mode, an area1 gradational display mode
according to a pixel division may be used, thus requiring an
increased number of electrodes corresponding to the pixel division
and arrangement of driver ICs and output electrodes at a higher
density. In such cases, the circuit connection structure according
to the present invention may preferably be used not only for data
signal side ICs but also for scanning signal side ICs.
FIG. 5 is a partial sectional view of a liquid crystal display
apparatus including a drive circuit connection structure according
to a second embodiment of the present invention, wherein copper
foil patterns 17 and connection electrodes 19 on a circuit board 3
are connected with a solder 20. Other members denoted by identical
numerals as in FIG. 2 represent identical or like members as in
FIG. 2, and 23 represents an aperture formed in a polyimide film
carrier 4 at the soldering portion.
FIG. 6 is a partial sectional view of a liquid crystal display
apparatus including a drive circuit connection structure according
to a third embodiment of the present invention, wherein the
connection structure is protected by a resinous sealing agent 21
and reinforced by a reinforcing plate 22. In this instance, after
applying the resinous sealing agent 21, the reinforcing plate may
be bonded to the glass substrate 1a and the circuit board 3 from
the back sides, so as to prevent the breakage of the electrical
connection even when a stress is applied to the circuit board 3. It
is particularly preferred to adopt the reinforcement structure with
the reinforcing plate 22 in case where one side of electrodes
(output electrodes in this embodiment) of the driver IC 5 are
bonded to electrode terminals on the substrate 1b without using a
flexible wiring member as in this embodiment.
FIG. 7 is a sectional view a drive circuit connection structure
according to a fourth embodiment of the present invention, wherein
a driver IC 5 is connected to a flexible wiring member 4a with an
anisotropic conductive adhesive 26. The connection structure may be
incorporated in a liquid crystal display apparatus having a
sectional structure as shown in FIG. 8, wherein the projecting
electrodes 13 of the driver IC 5 are thermally pressure-bonded to
electrode terminals 12 on the glass substrate 1b via an anisotropic
conductive adhesive 14, and conductors 17 on the flexible wiring
member 4a are thermally pressure-bonded to connection electrodes 19
on a circuit board 3.
In FIG. 8, the conductors (copper foil patterns) 17 are disposed on
an upper surface of the flexible wiring member 4a, and
correspondingly the circuit board 3 is disposed above the flexible
wiring member 4a (on the side having the conductors 17).
FIG. 9 is a partial sectional view of a liquid crystal display
apparatus including a drive circuit connection structure according
to a fifth embodiment of the present invention, wherein a
reinforcing plate 30 is disposed along and bonded to the circuit
board 3, the driver IC 5 and another substrate 1a in a structure
similar to the one shown in FIG. 8. The resultant structure is
resistant to a stress applied to the circuit board 3, etc., thus
being able to avoid a breakage of the electrical connection
similarly as in the embodiment of FIG. 6.
FIG. 10 is a partial sectional view of a liquid crystal display
apparatus including a drive circuit connection structure according
to a sixth embodiment of the present invention, wherein electrode
terminals 12 on the glass substrate 1b and the projecting
electrodes 13 on the driver IC 5 are thermally pressure-bonded to
each other via an anisotropic conductive adhesive 14 after
positional alignment therebetween, input electrodes 29 of the
driver IC 5 are electrically connected to connection electrodes on
the circuit board 3 with conductive wires 28, and a reinforcing
plate 30 is provided to fix the glass substrate 1a, the driver IC
and the circuit board 3 by bonding similarly as in FIG. 9.
Finally, an organization of a liquid crystal display apparatus
including a liquid crystal display panel as described above
together with a control system thereof will be briefly described
with reference to a block diagram of such a liquid crystal display
apparatus, for example, shown in FIG. 11.
Referring to FIG. 11, a liquid crystal display apparatus, such as a
color display apparatus, may include a liquid crystal panel 1 as
described above according to the present invention, to which are
connected a scanning signal application circuit 402 and a data
signal application circuit 403 which are sequentially connected to
a canning signal control circuit 406 and a data signal control
circuit 407, a drive control circuit 404 and then to a graphic
controller 405. From the graphic controller 405, video data and a
scanning scheme signal are supplied to the scanning signal control
circuit 406 and the data signal control circuit 407 via the drive
control circuit 404.
The video data is converted into scanning line address data and
display data by the scanning signal control circuit 406 and the
data signal control circuit 407, and the scanning scheme signal is
supplied as it is to the data signal application circuit 402 and
the data signal application circuit 403.
The scanning signal application circuit 402 applies a scanning
signal determined by the scanning scheme signal to the scanning
electrodes in a sequence determined by the scanning line address
data, and the data signal application circuit 403 applies data
signals having waveforms determined by a combination of the display
data determining white or black display states and the scanning
scheme signal to the respective data electrodes. These data signals
and scanning signals are supplied via flat cables 6 and 7 to
circuit board 3 and 10, whereby a picture display may be performed
on the liquid crystal panel 1 as shown in FIG. 1.
In the above, the circuit connection structure according to the
present invention has been described principally as one suitably
used in a liquid crystal display apparatus but may also be suitably
incorporated in other display apparatus inclusive of those
including self-light emission-type flat display panels as
represented by an EL-display panel and a plasma display panel.
As described above, according to the present invention, by
connecting electrode terminals disposed on a peripheral side of a
display panel to first electrodes on one side of a drive
semiconductor device with, e.g., an anisotropic conductive
adhesive, the electrode terminals and the drive semiconductor
device may be connected without a flexible wiring member, thus
ensuring a small connection pitch.
On the other hand, second electrodes on the other side of the drive
semiconductor device may be connected to a flexible wiring member,
and the flexible wiring member is connected to a circuit board on a
supply side with a solder or an anisotropic conductive adhesive,
the power and signal can be supplied to the driver semiconductor
device at a low impedance. As a result, even if a display panel,
such as a liquid crystal display panel, is enlarged in area1 size
and driven at a higher speed, drive waveforms can be transmitted to
pixel electrodes of the display panel without transmission delay or
deformation of drive waveforms. Further, in case of supplying
picture data for a display panel of a higher definition it is
possible to obviate a mal-function during data transmission.
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